1. Field of the Invention
This invention relates to an electric steam iron and in particular, to the boiler thereof used for generating steam.
2. Background Information
Generally, most electric steam irons in use today employ a "flash" steam system wherein water contained in a water reservoir is dropped directly on a hot soleplate to generate steam. The generated steam temperature is usually superheated and is directly proportional to the soleplate temperature. It has been found that relatively high temperature superheated steam is not as effective for ironing garments as steam at or near saturated conditions (100.degree. C.). It has been also determined that saturated steam with some moisture content can relax the fabric of the garment being ironed and result in a more satisfactorily ironed garment.
To generate lower steam temperature in conventional irons the soleplate temperature must be reduced which sometimes results in water spotting and inadequate heat for the fabric being ironed.
To overcome the disadvantages of a "flash" steam system, irons having separate boilers for generating steam and which are heated and controlled independently of the soleplate have been designed. Examples of such prior art illustrating separate soleplate and boiler heaters are found in U.S. Pat. Nos. 2,387,757, 2,499,835, and 3,263,350. The addition of a second heater dedicated to the generation of steam has typically increased the elevational profile of the iron, making the iron more expensive to manufacture, and less aesthetically attractive.
Further, it has been found that when operating an electric iron at or near saturation conditions, the generated steam must be directed through a relatively tortuous path to separate relatively large droplets of condensation from the steam. If relatively large droplets or slugs of water are not separated from the steam and are discharged from the iron, these droplets tend to cause water spotting of the fabric being ironed.
It is, therefore, an object of this invention to manufacture an electric steam iron that has a first heater for generating steam and a second heater for heating the soleplate of the iron. It is a further object to produce steam at or near its saturation temperature. It is still a further object of the invention to generate steam at or near its saturation temperature and to effectively remove relatively large droplets of water entrained in the steam before the steam is discharged onto fabric.